Robot system and method for controlling a robot system

ABSTRACT

The present invention relates to a robotic system having at least one robotic arm, a control unit for controlling the robotic arm and a robotic arm sensor system, wherein the controller and robotic arm sensor system are designed to respond to predetermined haptic gestures of the user acting on the robotic arm in such a way that the robotic system performs at least one predetermined operation associated with the haptic gesture.

The present invention relates to a robotic system and a method forcontrolling a robotic system.

Usually, robotic systems are programmed in such a way that an operatorenters the necessary commands for the robotic system, e.g. as part of aprogramming or parameterization of the robotic system, by means of aseparate device, for example a computer, via a corresponding userinterface.

Furthermore, it is known to provide separate input devices directly onthe robotic system, for example directly on a robotic arm, such asswitches or keys, by means of which different operations can beactivated on the robotic arm and then performed. Such operations includee.g. movement of the robotic arm in space, emergency shutdown in case ofdanger, confirmation of a position, etc. . The operator always moves inthe immediate vicinity of the robotic system.

In addition, in a direct human-robot collaboration (HRC), only thepositioning of the end effector on the robotic arm is usually performedby haptic interaction between human and robot, in which the humanmanually moves the robotic arm to the desired position.

A continuing and usually more complex interaction is currently onlycarried out via additional input devices, as is the case with theprogramming or parameterization of the robotic system.

For this type of collaboration, it is necessary for the user torepeatedly switch back and forth between robot guidance and theactuation of the additional input device. This is cumbersome and canalso lead to dangerous situations, as the user has to concentrate on theinput devices again and again and let the potentially moving robot outof sight.

Based on that, it is an object of the present invention to expand theinteraction between humans and a robotic system and thereby to providean improved HRC environment. In addition, a simpler operability of therobotic system shall be provided to control various operations that areeither performed by the robotic system itself or in a functionalconnection therewith.

This object is achieved with a robotic system having the featuresaccording to claim 1 and with a method for controlling a robotic systemhaving the features according to claim 10.

The invention thus proposes a robotic system comprising at least onerobotic arm, a control unit for controlling the robotic arm, and arobotic arm sensor system, wherein the controller and robotic arm sensorsystem are adapted to respond to predetermined haptic gestures of theoperator acting on the robotic arm, so that the robotic system performsat least one predetermined operation associated with the haptic gesture.

For this purpose, the allocations between the possible haptic gesturesand the associated operations are stored in a memory that cooperateswith the controller.

The invention is preferably, but not exclusively, directed to roboticsystems designed for manual guidance by an operator. These haveintegrated force and torque sensors, which can be used according to theinvention and accordingly also adapted to receive the external forces,moments and torques acting by the haptic gestures of an operator on therobotic arm or only on parts of its arm members and to forward the sameto the control unit.

The forces, moments and torques can be detected by various sensors, suchas force measuring sensors, torque sensors, etc., which are locatedeither in the joints, in the base and/or generally in the structure ofthe robotic system. It is also conceivable that the housing structure ofa robotic arm is at least partially covered with a tactile skin, whichallows an input via one or more fingers.

In one embodiment, the control unit may accordingly be designed toassign the forces and/or moments generated by the haptic gestures todifferent operations depending on their respective directions and/ortheir respective course.

In a further embodiment, the control unit may be configured to assignthe forces and/or moments generated by the haptic gestures to differentoperations depending on their respective variables.

It is also possible that the control unit is designed to assign adifferent chronological sequence of haptic gestures to differentoperations, which are then carried out in a logical sequence.

The invention has the advantage that the sensor system already presentin these robotic systems are not only used to support a mere positioncontrol of the end effector and trajectory control of the robotic arm,both during operation and during programming, but can also be used, byan operator by means of haptic gestures, such as pulling, pressing,pushing, turning, to receive deliberately generated forces, moments andtorques and to supply the same to a further abstract interaction betweenhumans and the robotic system.

In a preferred embodiment, the robotic system, comprises a displaydevice with a graphical user interface, in its simplest form a computerconnected to the robotic system for control or programming purposes.According to the invention, the haptic gestures can then be assigned toa control on the graphical user interface. The control can be done intwo or three dimensions. In this embodiment, the operator can move acursor or a menu navigation on the user interface by targeted spatiallydirected pressure on the robotic arm.

The operator does not necessarily need the help of a graphical userinterface in order to receive corresponding confirmations or feedback ofhis actions from a programming system.

Thus, it can be provided according to the invention that the controlunit is designed to generate a feedback in response to the hapticgesture.

The feedback can be auditory and/or visual.

Preferably, however, this feedback can also be made hapticallydetectable by the operator. For such a case, the control unit isconfigured to vary the degree of compliance for the mobility of therobotic arm while the haptic gesture is applied thereto.

For example, if the operator pushes laterally against an arm member ofthe robotic arm, the resistance of the robotic arm to the pressureexerted by the haptic gesture can be successively increased to providethe operator with appropriate feedback. The increase in the resistancecan be effected by a corresponding control of drive units arranged inthe hinge points between arm members of the robotic arm.

The feedback generated thereby can then serve as an orientation in morecomplex interactions, such as haptic menus, or as a type ofacknowledgment when a predetermined haptic gesture has been detected bythe control unit.

The invention further relates to a method for controlling a roboticsystem, which has at least one robotic arm, a control unit forcontrolling the robotic arm and a robotic arm sensor system, comprisingthe steps:

manipulating the robotic arm by at least one predetermined hapticgesture;

generating signals by the robotic arm sensor system in response to thepredetermined haptic gesture;

transmitting the signals into the control unit; and

assigning the signals to different predetermined operations by thecontrol unit.

Further steps of the method according to the invention comprise

generating at least one feedback in response to the differentpredetermined operations; as well as

adjusting of the compliance of the robotic arm depending on apredetermined haptic gesture.

It will become clear that the invention uses components already existingin the robotic system in a simple manner in order to expand the area ofinteractions for such a robotic system.

In principle, there are no limits to the way in which predeterminedhaptic gestures are to be assigned to various predetermined operations.

The principle of haptically controlled guidance of the robotic arm,while the robotic arm itself functions as an input device, can be usedfor various interactions.

Thus, such a control can be used for example in the programming of therobotic system and also in the parameterization of individual operationsto be performed, which can reduce setup times while minimizing costs forsuch robotic systems.

In addition, it is conceivable that during operation the robotic systemis haptically controlled in a HRC-environment. For example, a strongblow by the operator against the robotic arm may signal an emergency inthe work area, forcing the robotic system to shut down. This shortensthe response time because the operator does not need to get close to anemergency switch to operate it.

Further features and advantages will become apparent from the followingdescription of an embodiment shown with reference to the only FIG. 1.

FIG. 1 shows a perspective view of a multi-axle lightweight robot, whichis composed of a plurality of articulated arm members 10 connected toone another.

Using the example of the front (distal) member 20, which cooperates withan end effector, not shown, the possible directions are indicatedschematically, which can act by haptic gestures on the robotic system.

Thus, it is possible for an operator to exert tensile or compressiveforces on the member 20 in the X-, Y-, Z-directions.

A light push on the member 20 in the Z-direction, for example, maysymbolize the pressing of a push-button, this haptic gesture is thenassigned to a start command that activates a predetermined operation.

By pushing the member 20 sideways to the left (L) or to the right (R),the operator can be guided through a complex menu of a graphical userinterface on a display device, not shown, such as the screen of acomputer. By pressing in the Z- or Y-direction, the entry selected inthe graphical menu by these haptic gestures can then be confirmed.

It is also possible to transmit the movement of the member 20 in theX-Y-plane to the movement of a cursor on a screen and to perform a“mouse click” by pressing in the Z-direction.

Furthermore, it is possible for the operator to make a haptic rotation Ron the member 20, the amount of torque applied thereby being able to beused as a signal for the strength of a parameter to be selected by thisrotation. The haptic rotation in R-direction simulates a rotary knob.

For an emergency, it may be provided that an operator simply beatsagainst the robotic arm, indicated by arrow P. The robotic systemrecognizes by the force or the acceleration that it refers to such anemergency and then immediately stops its motion.

The haptic gestures are not limited to the foremost arm member 20. Inprinciple, each individual arm member 10 may be provided with suchfunctionality.

In addition, it is possible that the behavior of physical surfaces, keysor rotary knobs can be simulated by virtual, as freely programmableresistors when moving the robotic arm. In this way, the robotic systemcan be used by itself as an input or control device to activate complexsystems and operations that are in a close functional relationship withthe robotic system or its desired functionality.

1. Robotic system having at least one robotic arm, a control unit forcontrolling the robotic arm and a robotic arm sensor system,characterized in that the control unit and robotic arm sensor system aredesigned to respond to predetermined haptic gestures of the user actingon the robotic arm so that the robotic system performs at least onepredetermined operation associated with the haptic gesture.
 2. Roboticsystem according to claim 1, comprising a graphical user interface,wherein the haptic gesture is associated with a control on the graphicaluser interface.
 3. Robotic system according to claim 1, in which theforces and/or moments generated by the haptic gesture are assigned todifferent operations depending on their respective directions. 4.Robotic system according to claim 1, in which the forces and/or momentsgenerated by the haptic gesture are assigned to different operationsdepending on their respective variables.
 5. Robotic system according toclaim 1, in which a different chronological sequence of haptic gesturesis assigned to different operations.
 6. Robotic system according toclaim 1, in which the control unit is adapted to generate a feedback inresponse to the haptic gesture.
 7. Robotic system according to claim 6,in which the feedback is auditory and/or visual.
 8. Robotic systemaccording to claim 6, in which the feedback is formed to be hapticallydetectable.
 9. Robotic system according to claim 8, in which thecompliance of the robotic arm is variable.
 10. Method for controlling arobotic system comprising at least one robotic arm, a control unit forcontrolling the robotic arm and a robotic arm sensor system, comprisingthe steps: manipulating the robotic arm by at least one predeterminedhaptic gesture; generating signals by the robotic arm sensor system inresponse to the predetermined haptic gesture; transmitting the signalsinto the control unit; and assigning the signals to differentpredetermined operations by the control unit.
 11. Method according toclaim 10, further comprising: generating at least one feedback independence on the different predetermined operations.
 12. Methodaccording to claim 11, further comprising: adjusting the compliance ofthe robotic arm depending on a predetermined haptic gesture.